Culturable Commanded Area (CCA) definition — identify the incorrect deduction when computing CCA from Gross Commanded Area (GCA).

Introduction / Context:
Planning an irrigation project requires distinguishing the land actually cultivable under a canal system. Culturable Commanded Area (CCA) is derived from the Gross Commanded Area (GCA) by excluding permanently unculturable categories, not land that is simply left uncropped in a given season (fallow).

Given Data / Assumptions:

• GCA includes all land topographically commanded by the project.
• We remove areas that are intrinsically not cultivable.
• Fallow land is considered potentially cultivable (culturable).

Concept / Approach:

CCA = GCA − (permanently unculturable lands such as settlements, roads, forests, rocky patches, water bodies, alkaline wastelands). Seasonal fallow remains within CCA because it can be cultivated when water and agronomy permit. Hence subtracting fallow is incorrect.

Step-by-Step Solution:

Verification / Alternative check (if short method exists):

Check project planning manuals: CCA serves as the basis for cropping intensity and water duty; fallow is part of the rotation within CCA.

Why Other Options Are Wrong:

Options A, B, C, and E correctly identify unculturable deductions. Only D conflicts with standard definitions.

Common Pitfalls (misconceptions, mistakes):

Confusing “fallow” with “unculturable”; miscounting double-cropped area as additional CCA (it affects cropping intensity, not CCA).

Final Answer:

Subtract fallow land.